Issue 69 Public Health Newsletter of Water Quality Research Australia April 2013 In this Issue: Hydraulic Fracturing and Water Supplies Hydraulic Fracturing and Water Supplies 1 Extreme Weather and Waterborne 2 The US EPA has delivered the first progress report Outbreaks for a research study on the potential impacts of Animal Waste, Water Quality and 5 hydraulic fracturing (commonly known as fracking) Human Health on drinking water resources (1). The study was News Items 8 initiated following a request from the US Congress in From The Literature 9 late 2009, and the final design was developed during Alzheimer’s Disease * an extensive consultation process with stakeholders Amoebae * and a series of technical workshops. The final report Arsenic * from the study is scheduled for delivery in 2014, but Chemical Contamination * delays in establishing some components suggest that Cholera * not all aspects will be completed by the due date. Disinfection Byproducts * Endemic Gastroenteritis * Fluoride * Hydraulic fracturing is a process by which fractures Household Water Treatment * are deliberately induced in underground oil or gas- Indicator Organisms bearing strata through a process involving pumping Mycobacteria water-based fluids at high pressure into drilled wells. Outbreaks Sand is added to the fluid as a “proppant” to keep the Protozoa fractures open when the pressure is relaxed. The Rainwater network of fine fractures provides increased Water Intake connection to the surrounding strata and enables Water Quality recovery of a larger amount of oil or gas from the well. The process was developed in the US in the late Mailing List Details 20 1940s and has been used worldwide to enhance production from “conventional” oil and gas wells Editor Martha Sinclair since that time. Conventional oil and gas deposits are Assistant Editor Pam Hayes located in relatively permeable strata and most of the available fuel resource is accessible through the * Summaries of web bonus articles on these topics natural porosity of the geological formation. In this are contained in the PDF version of Health Stream context fracking is generally used to enhance on the WQRA website. recovery as the yield begins to decline and the well approaches the end of its productive lifetime. www.wqra.com.au Fracking may also be used in construction of drinking water wells under some circumstances. HEALTH STREAM APRIL 2013 PAGE 1 WATER QUALITY RESEARCH AUSTRALIA Over the last two decades, advances in technology concerns about energy security and heavy have permitted a much broader application of dependence on supplies from politically turbulent fracking to exploit “unconventional” oil and gas areas of the world. As a result, production of natural deposits. These deposits are located in relatively gas from unconventional sources rose from 28% to impermeable formations of shale, coalbeds or tight 50% of total US natural gas production between 1998 sands of variable depth and thickness. Many cannot and 2008. This increase was initially based on be effectively exploited using traditional vertical gradual development of coalbed and tight sand gas wells as the low permeability means that only a small resources, but since 2005 there has been a very rapid fraction of the resource is accessible from a single increase in production of natural gas from shale well. The ability to identify and accurately deposits. While the basic principles of the fracking characterise such deposits has been increased by the process have remained the same since the 1940s, development of modelling techniques using magnetic modern fracking practices involve use of a larger and seismic data which allow 3-dimensional mapping range of chemical additives in fracking fluid, much to depths of several thousand metres below ground higher pressures and often greater drilling depths level. In addition, technical advances in drilling than used in the past. Shale beds are generally located methods have made it possible for wells to be drilled at greater depths than coalbeds, and thus require horizontally (after drilling an initial vertical shaft) or more extensive drilling, use of higher pressures to in an S-shape to increase access oil or gas resources create fractures and larger volumes of fracking fluid. in low permeability strata. The horizontal leg of a For shale gas drilling, each drill head and pad well can be extended up to 3,000 metres from the typically requires 2-4 hectares (5-10 acres) of land wellhead, and multiple horizontal wells can be drilled and 19 ML (5 million gallons) of water for each outwards from a single drilling stage. round of fracking. Delivery of construction materials and sufficient proppant, water and chemicals for one After drilling and casing the well, fracking is round of fracking has been estimated to require over performed by detonating small explosive charges at 1600 truckloads per well, with a further 750 intervals along the horizontal section to create breaks truckloads needed to remove the liquefied natural gas in the casing. Fracking fluid containing proppant and and fracking wastewater. other additives is then pumped down the well at high pressures, creating fractures in the surrounding strata The rapid expansion of the shale gas industry in the around each break in the casing. About 15 to 30% of US and the use of fracking technology have raised the fracking fluid returns to the surface (termed many public concerns, including disquiet over flowback water) and requires storage and disposal. impacts on the quality and quantity of water supplies Water from the underground deposits is also and potential environmental or human health impacts extracted from the well during gas production of exposure to chemicals used in the fracking process (termed produced water). The produced water or released from underground strata. A number of commonly has high salinity and may also contain a rural communities have experienced adverse effects range of contaminants released from the underground on infrastructure and local amenity values from strata, potentially including arsenic, barium, intensive drilling developments in previously quiet hydrocarbons and naturally occurring radioactive farmland and low density residential areas. On the elements. Fracking can be repeated several times other hand, some individuals, communities and state during the lifetime of a well, with new fractures governments have welcomed the financial benefits of being created at different locations each time to the shale gas boom at a time of high unemployment provide access to more of the oil or gas deposit. and decreased activity in the US economy. The issue has also divided the environmental movement, with High oil prices in the 1990s provided a driver to some groups supporting shale gas development exploit the large “unconventional” oil and gas because the resultant natural gas (predominantly deposits which exist in many countries. In the US, methane) produces less greenhouse gases than coal or expanded use of these resources was also spurred by oil when burned to generate electricity, while others HEALTH STREAM APRIL 2013 PAGE 2 WATER QUALITY RESEARCH AUSTRALIA oppose substitution of one type of fossil fuel for Well Injection: What are the possible impacts of the another, arguing it will further delay the eventual injection and fracturing process on drinking water changeover to cleaner alternatives. resources? • accidental release to ground or surface water Public concerns have been exacerbated by the (e.g. well malfunction) provisions in the US federal Energy Policy Act of • fracturing fluid migration into drinking water 2005 which exempted chemicals used in oil, gas or aquifers geothermal energy production activities from • formation fluid migration into drinking water requirements in the underground injection control aquifers, mobilisation of subsurface program of the Safe Drinking Water Act. Exemptions formation materials into aquifers) are also present in six other federal regulations relating to environmental pollution, remediation and Flowback and Produced Water: What are the possible disclosure requirements. Although some information impacts of surface spills on or near well pads of is available on the content of fracking fluids, it is flowback and produced water on drinking water common for companies to withhold information resources? • relating to proprietary additives. Among the release to surface and ground water • chemicals which have been identified, a number have leakage from onsite storage into drinking toxic properties and could potentially be harmful to water resources • human or environmental health, depending on improper pit construction, maintenance exposure levels. There have been a number of reports and/or closure of drinking water contamination in areas where Wastewater Treatment and Waste Disposal: What are fracking is occurring, but the industry has the possible impacts of inadequate treatment of consistently denied any links to fracking activities, hydraulic fracturing wastewaters on drinking water saying the separation of the deep shale layer from resources? shallow groundwater aquifers makes it impossible for • surface and/or subsurface discharge into fractures to penetrate to the aquifer. To date there surface and groundwater has been little peer reviewed research on water • incomplete treatment of wastewater and solid quality and quantity impacts, or on human or residuals environmental health effects related to fracking (2). • waste water transportation accidents The five